The four elements, oxygen, hydrogen, carbon, and nitrogen, make up nearly the whole bulk of the fluids and soft solids of the human body. A number of other elements, chiefly in a state of combination, and in much smaller quantities, enter into several of the tissues.
Binary Compounds – Thus, we have carbonic acid in blood, urine and sweat; and we have water universally diffused through the sys, tem, each of these substances being a binary compound, that is, composed of two elements.
Compounds of more than two Elements are widely distributed over the body; as,
Carbonate of Soda in serum, saliva, bile, mucus, sweat, and tears.
Carbonate of Lime in cartilage, bone, and teeth.
Phosphate of Lime in bones, teeth, and cartilage.
Phosphate of Iron in blood, gastric juice, and urine.
Chloride of Sodium in blood, brain, muscle, bone, cartilage and pigment.
Chloride of Potassium in blood, gastric juice, milk, and saliva.
Chloride of Calcium in gastric juice.
Sulphate of Potassa in urine, gastric juice, and cartilage.
Sulphate of Soda in sweat, bile, and cartilage.
Sulphate of Lime in bile, hair, and scarf-skin.
Oxide of Iron in blood, black pigment, and hair.
Organized Compounds.- Besides the above inorganic elements and compounds, several organized substances, or proximate elements, as they are called, exist largely in the body. The chief of these are albumen, fibrin, gelatin, mucus, fat, and casein. Others need not be named.
Albumen is found in great abundance in the human body. It is the raw material out of which the flesh and other tissues are made. The white of an egg, which is nearly pure albumen, is a good specimen of it.
Fibrin, when removed from the human body, changes from a soluble to an insoluble state. In other words, it coagulates in a kind of network. Nearly the same thing takes place constantly in the living body when the liquid fibrin leaves its soluble state, and is deposited as solid flesh. Fibrin bears the same relation to albumen that woolen yam does to wool; it is spun from it in the busy wheel of organic life. And the flesh or muscle is related to fibrin as the cloth is to yarn; it is woven from it in the vital loom. Fibrin has been called liquid flesh.
Gelatin exists largely in the ligaments, cartilages, bones, skin, and cellular tissue. When dissolved, five parts in one hundred of hot water, it forms a thick jelly. Isinglass is a form of gelatin obtained from the airbladder of the sturgeon and the codfish. Glue is still another ‘form of gelatin. It is extracted from the bones, and parings of hides, L ad the hoofs and ears of cattle, by boiling in water. Black silk, varnished over with a solution of gelatin, forms court-plaster.
Mucus is a sticky fluid secreted by the glandcells. It is spread over the surface of the mucous membranes, and serves to moisten and defend them from injury.
Fat consists of cells held together by cellular tissue and vessels, and contains glycerin, stearic acid, margaric acid, and oleic acid. It has no nitrogen. If the stearic acid be in excess, the fat is hard; if the oleic acid preponderate, it is soft. The stearine extracted from fat is used for making very hard candles.
Casein is abundant in milk and constitutes its curd. It is held in solution in milk by a little soda. When dried, it is cheese. It is found in blood, saliva, bile, and the lens of the eye. It forms the chief nourishment of those young animals which live on milk. It is found in peas, beans, and lentils. Vegetable and animal casein are precisely alike in all their properties. Fibrin and albumen contain almost exactly the same amount of oxygen, hydrogen, carbon, nitrogen, and sulfur, which is found in casein. This latter, when taken into the stomach, therefore, goes, without much change, to the formation of the albumen and fibrin of the body.
SOURCE: The Household Physician By Ira Warren